Work in this laboratory has been focused on the determination of three-dimensional structures of larger proteins in solution by NMR, with a particular emphasis on protein-protein, protein-ligand and protein-DNA complexes. A considerable effort has been placed on the development of three- and four-dimensional heteronuclear NMR to extend the application of NMR as a method for determining three-dimensional structures of proteins in solution beyond the limits of conventional two-dimensional NMR (-100 residues) to molecules in the 150- to 400- residue range, and to develop new NMR methods for determining long range order of priority, including the dependence of heteronuclear relevation data on diffusion anisotropy and the use of residual dipl couplings arising from magnetic susceptibility anisotropy. Solution structures of a number of proteins have been determined. These include the complexes of the transcription factors GAGA, Are A and HMG-I/Y with DNA, the DNA MuA binding domains of the transposase, the 30 kDa (259 residue) N terminal domain of Enzyme I of the PTS pathway, the 44 kDa ectodomain of gp41, and the N-terminal domain of HIV-1 integrase.